C5 Flashcards
What happens in an exothermic reaction?
Energy is transferred into the surroundings - exiting
Give examples of exothermic reactions
Combustion
Oxidation
Neutralisation
What happens in endothermic reactions?
Energy is taken from the surroundings
Give examples of endothermic reactions
Thermal decomposition - compound breaks down to form two or more substances when it is heated
Reaction of citric acid and sodium hydrogen carbonate
What is the energy level from reactants to products in an exothermic reactions
The reactants have more energy than the products
What is the energy level from reactants to products in an endothermic reaction
The reactants have less energy than the products
What is the activation energy
The minimum amount of energy that colliding particles must have for them to react.
What do bonds do in endothermic reactions
Bonds are broken
Less heat energy is released in making bonds in the products than is taken in when breaking bonds in the reactants
What do bonds do in an exothermic reaction
Bonds are formed
More heat energy is released in making bonds in the products than is taken in when breaking bonds in the reactants
What is the overall change in exothermic reactions
Negative
What is the overall change in endothermic reactions
Positive
